Last night I had a rather weird dream, wierder than usual. It was non-lucid, and the basic plot was something like this:

There was a giant paddle boat, with one large paddle at the front which was made out of k'nex. It was supposed to be eaten by a shark, but due to a 6-year old prophecising it, it did not happen. Because of this, the world was flooded. A short part with several people in an apartment with water up to their chests followed this.

The weird thing was that as soon as the dream started, I remembered the whole thing (like deja vu) but I remembered it as though I had read it in a book called Mortal Engines. During and shortly after the dream I was convinced that I had read this story about the boat somewhere before, but upon careful thought I realised that it was just too preposterous to have read.
Therefore, I can only conclude 3 possibilities:
A. The dream created a memory of me having read the book
B. I had really read the story somewhere
C. At the time I was reading Mortal Engines (several years ago) I had this dream, and because I had it again tonight, I remembered it as though I had read it in a book.
Personally, I think it's C, but I'd like some other opinions on this....

Anyone experienced anything like this before, or have an alternate theory?